Burner construction



May 12, 1970 H- w- JANSEN ETAL 3,511,587

BURNER CONSTRUCTION 2 Sheets-Sheet 2 Filed May 15. 1968 FIG. 3.

INVENTORS HERMANN W. JANSEN HELMUTH HILGER BY ATTORNEYS.

United States Patent 3,511,587 BURNER CONSTRUCTION Hermann W. Jansen,and Helmuth J. Hilger, Duren, Rhineland, Germany, assignors toZimmermann & Jansen G.m.b.H., Duren, Rhineland, Germany, a corporationof Germany Filed May 15, 1968, Ser. No. 729,295

Claims priority, application Germany, Oct. 3, 1967,

Int. Cl. F23d /02 U.S. Cl. 431-160 14 Claims ABSTRACT OF THE DISCLOSUREA burner for a hot blast stove disposed in an open chamber for admittingseparate supplies of air and fuel to an area outwardly of said chamber.The burner includes an inner cone member which carries a shell in spacedrelation therewith so as to define an inner passageway between the innercone member and the shell for one of the gaseous mediums and an outerpassageway between the shell and the peripheral wall of the openchamberfor the other gaseous medium. The inner cone member is axially movablefrom one end position thereof in which it closes the open chamber to aplurality of other positions in which both inner and outer passagewaysare in fluid communication with the area outwardly of the chamber. Theextent of such axial movement controls the velocity of the gaseousmedium through the outer passageway and a tube type valve is provided inthe inner passageway to independently control the velocity of thegaseous medium therein. The shell is shaped so as to provide differentdirections of flow for the two gaseous mediums in order to obtain a moreintimate mixing thereof.

BACKGROUND OF THE INVENTION In conventional burner arrangements for hotblast stoves, the burner is usually positioned in such manner that theflames produced during the combustion are directed against thecombustion chamber wall opposite the burner exit. This portion of thecombustion chamber wall is of a critical nature because the same issubjected to very high temperatures during the ON GAS cycle of the hotblast stove and to very cold temperatures of the cold blast during theON BLAST cycle. These significant variations in temperature, from veryhot to very cold, frequently cause injury to the brick work of thecombustion chamber and also cause what is known as short circuiting ofthe hot blast stove, namely, the diametrical flow of flue gas throughthe wall of the combustion chamber into the lower part of the stove andinto the chimney so that the heat is not transferred to the brick work.When such short circuiting takes place, it is often accompanied by adeterioration of the steel support for the brick work which in turnoften results in a complete breakdown of the brick work. Another seriousdeficiency in conventional burners is that these provide for onlylimited control of the path and velocity of both mediums passing throughthe burner, namely, air and fuel which in turn makes intimate mixing ofthe two mediums virtually unachieveable. Further, the inability toobtain complete mixing because of the lack of control of the flowvelocities of the air and the fuel produces unfavorable conditions bothas regarding the flames of combustion as well as the combustion itself.

SUMMARY OF THE INVENTION The burner construction of the presentinvention eliminates the several deficiencies in conventional burnerarrangements described above. In accordance with the invention, theburner comprises separate passages for the air and the fuel,respectively, with each passage being controlled independently of theother so that the velocity of each of the two mediums can be controlledindependently of the other. The direction of flow of both mediums in theburner provides relative flow directions for both mediums assured toprovide intimate mixing.

The above results are achieved by providing an inner cone which forms aclosure member for the open chamber which leads into the combustionchamber, This inner cone has a conical shell attached thereto with aninner passageway for one of the mediums being defined between the shelland the inner cone member and an outer passageway for the other mediumbeing defined between the shell and the peripheral wall of the openchamber. Axial movement of the inner cone member provides communicationbetween both inner and outer passageways and the combustion chamber. Theextent of axial movement controls the velocity of the medium in theouter passageway while an independently controllable tube valve controlsthe velocity of the medium in the inner passageway.

With such arrangement the direction of the fuel and the air into thecombustion chamber is such that the flames shoot in a generally upwarddirection and do not touch directly the wall of the combustion chamber.Accordingly, the difference in temperature between the ON GAS and ONBLAST cycle as felt by the combustion chamber wall is far lower than inconventional prior art burner arrangements. Axially moving cone shapedmembers in burners per se have been used before as shown in U.S. Pat.No. 1,779,647, but without any of the additional improvements andrefinements of the present construction.

The vertical burner construction in accordance with the invention,because of its arrangement, can be located in any one of a plurality ofpositions. For example, such burner can be installed in the dome of thestove and could also be most advantageously used in stoves with internalas well as external combustion chambers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross-sectioinalview of the burner in accordance with the invention;

FIG. 2 is a view similar to FIG. 1 showing the burner in open position;and

FIG. 3 is a view similar to FIG. 2 of another embodiment of the burner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,there is shown in FIG. 1 a portion of furnace wall 10 having an openchamber 12 in which there is mounted a burner 14. Burner 14 comprises aninner cone member 18 having a stem 20 operatively connected to anactuator 22 for axially moving inner cone member 18 from its lowermostposition as shown in FIG. 1 wherein it defines a closure for chamber 12to selective upper positions in which an air fuel mixture controlled bythe burner is admitted into combustion chamber 16.

Inner cone member 18 is provided with a shell 24 connected in spacedrelation to inner cone member 18 by means of flat iron bars 26. Shell 24comprises an upper conical portion 27 and a downwardly extending tubularportion 28, the latter being in telescopically sliding relation withinner tube 30 of the burner. An inner passageway 32 is defined betweeninner cone member 18 and shell 24 and an outer passageway 34 is definedbetween shell 24 and peripheral wall 36 of chamber 12. Inlet means 38 isin fluid communication with outer passageway 34, and inlet means 40,generally opposite to inlet means 38, is in fluid communication withinner passageway 32. Inlet means 38 and 40 are connected to the suppliesof the two mediums passing through the burner, namely, air and fuel.

In the position of the burner shown in FIG. 1, inner cone member 18defines a closure for chamber 12, there being provided suitable seatingmeans 42 at the upper ends of peripheral wall 36. Upper edge 44 ofconical shell 24 is in sliding relation with peripheral wall 36 ofchamber 12. As the burner is opened in response to upward axial movementof inner cone member 18 by means of previously mentioned actuator 22,upper edge 44 of shell 24 glides along peripheral wall 36 and, aftersuflicient axial movement is imparted, upper edge 44 will pass beyondseating means 42 establishing fluid communication between innerpassageway 32 as well as outer passageway 34 with combusition chamber16.

As such axial movement continues, it will correspondingly increase theexit opening from outer passageway 34 into combustion chamber 16. Thus,with a constant volume of fluid medium, such as for example air, beingadmitted through inlet means 38, the velocity of such medium can bevaried by axial movement of the inner cone member, with maximum velocityexisting immediately following the passage of upper edge 44 beyondseating means 42 down to the minimum value for such velocity when theaxial movement has reached its final position as shown in FIG. 2. Thus,it is seen that velocity of the medium admitted through inlet means 38can be varied by the above described axial movement, with the desiredvelocity of the medium being obtained at the primary combustion zone,where the mediums of the combustion mixture are burnt.

Axial movement of inner cone member 18 also creates fluid communicationbetween inner passageway 32 and combustion chamber 16, whereby the fluidmedium, such as for example gas, admitted through inlet means 40 passesthrough inner tube 30 and inner passageway 32 into the combustionchamber 16.

As previously stated, downwardly extending tubular portion 28 of shell24 is telescopically movable with respect to inner tube 30 of theburner. Such inner tube 30 is provided with a tube type (Rohrschieber)valve 46 which is in gliding relation with the inner periphery of tube30. Valve 46 is operatively connected through linkage rods 48 toactuator means for independently imparting axial movement to valve 46.Such axial movement of valve 46 controls the velocity of the mediumpassing through inner passageway 32 and out into the combustion chamber.In FIG. 2, valve 46, as shown by the full lines, is in its lowestposition in which the fluid medium admitted through inlet means 40passes into combustion chamber 16 through passageway 32 at a maximumsection thereof to provide minimum medium velocity. The uppermostposition of valve 46 is shown by the dashed lines in FIG. 2.

By means of the arrangement and construction of burner 14 isaforedescribed, it is clear that the velocity of both mediums admittedinto combustion chamber 16 are adiustable, independently of each other,to the optimum values as may be dictated by the requirements of theblast furnace operation. As best shown in FIG. 2 the fluid mediumintroduced into combustion chamber 16 through inner passageway 32 is inan oblique direction as indicated by arrow 50. On the other hand, thefluid medium introduced into combustion chamber 16 through outerpassageway 34 is in the direction of arrows 52. The difference in thedirections of both mediums forms a whirling motion resulting in athorough and intimate mixing of the two mediums. Thoroughness of themixing is further increased by the exact control of the velocity of bothfluid mediums available in accordance with the burner construction forthe reasons described above. The net result obtained is nearly completecombustion and most efficient operation of the burner.

The burner in accordance with the present invention also enables theprovision of convenient cooling means for the burner elements. Morespecifically, a peripheral passageway 54 is defined in surroundingrelation with chamber 12 in which passageway there is provided spiralguide means 56 which is connected to a circulating cooling system, whichenables the passage of a coolant at a high velocity around peripheralwall 36 of chamber 12, which coolant is admitted as at 57a and exits asat 5712. It will also be noted that the peripheral walls of inner conemember 18 are hollow, defining a passageway 58 through which a coolantcan be circulated, which coolant is admitted and exits through suitablepassages in stem 20.

FIG. 3 represents a modification of the burner construction of FIG. 1,in accordance with which a more intimate and thorough mixing of the twofluids is obtained. The burner construction in FIG. 3 is substantiallyidentical to that of FIG. 1 and is further provided with acircumferential baffle 59 on inner cone member 18, slightly above theupper end of inner passageway 32. Battle 59 performs the function ofdeflecting the gas which exits from inner passageway 32 so that ittravels in the direction shown by arrow 60-. In conjunction with suchmodified burner construction, furnace wall 10 is also modified to defineimmediately above chamber 12 a diverging section 62 generally parallelto upper conical portion 27 and a converging section 64. Such modifiedfurnace wall conformation directs the air exiting out of outerpassageway 34 in the direction shown by arrow 66. The modifications inburner construction and furnace wall conformation shown in FIG. 3 causethe two mediums entering the combustion chamier to travel in directionsgenerally perpendicular to each other resulting in increasedthoroughness of mixing as compared to the embodiment in FIGS. 1 and 2 inwhich the air and gas confront each other at an angle substantially lessthan degrees. With the arrangement shown in FIG. 3 the two mediumvelocities can be adjusted and a thoroughness of mixing can be obtainedso as to produce a desirable short flame not produceable in theembodiments of FIGS. 1 and 2.

While we have herein shown and described the preferred embodiments ofour invention, it will be understood that the invention may be embodiedotherwise than as herein specifically illustrated or described, and thatin the illustrated embodiments certain changes in the details ofconstruction and in the form and arrangement of parts may be madewithout departing from the underlying idea or principles of thisinvention within the scope of the appended claims.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

1-. A burner disposed in an open chamber for admitting separate suppliesof a pair of gaseous mediums to an area outwardly of said chambercomprising,

(a) an inner cone member,

(b) a shell carried by said inner cone member in spaced relationtherewith whereby to define an inner passageway between said inner conemember and said shell and an outer passageway between said shell and theperipheral wall of said chamber,

(c) said inner cone member being axially movable to a plurality ofpositions in which said inner and outer passageways are in fluidcommunication with said area outwardly of said chamber,

(d) said shell having an upper conically shaped portion for providingdifferent directions of flow for said gaseous mediums admitted into saidarea from said inner and outer passageways, respectively, wherebyintimate mixing of said mediums is obtained,

(e) said peripheral wall of said open chamber being cylindrical wherebythe size of the opening of said outer passageway into said area iscontrolled by the extent of said inner cone member axial movement forcorrespondingly adjusting the velocity of the gaseous medium admittedthrough said outer passageway, and

(f) a valve provided in said inner passageway for independentlycontrolling the velocity of the gaseous medium flowing therethrough.

2. A burner disposed in an open chamber for admitting separate suppliesof a pair of gaseous mediums to an area outwardly of said chambercomprising,

(a) an inner cone member,

(b) a shell carried by said inner cone member in spaced relationtherewith whereby to define an inner passageway between said inner conemember and said she l and an outer passageway between said shell and theperipheral wall of said chamber,

(c) said inner cone member being axially movable to a plurality ofpositions in which said inner and outer passageways are in fluidcommunication with said area outwardly of said chamber,

(d) said shell having an upper conically shaped portion for providingdifferent directions of flow for said gaseout mediums admitted into saidarea from said inner and outer passageways, respectively, wherebyintimate mixing of said mediums is obtained,

(e) said peripheral wall of said open chamber being cylindrical wherebythe size of the opening of said outer passageway into said area iscontrolled by the extent of said inner cone member axial movement forcorrespondingly adjusting the velocity of the gaseous medium admittedthrough said outer passageway,

(f) a fixed inner tube defining a partition between said inner and outerpassageways,

(g) said shell having a lower tubular portion in telescoping relationwith said inner tube for guiding said shell during axial movement ofsaid inner cone member, and

(h) a tube type valve provided for movement along the inner surface ofsaid inner tube for controlling the velocity of the gaseous mediumflowing through said inner passageway.

3. A burner in accordance with claim 2, wherein said area outwardly ofsaid chamber is the combustion chamber of a hot blast stove and whereinsaid gaseous mediums comprise air and fuel, respectively, and whereinsaid inner cone member is axially movable to a position in which itdefines a closure between said open chamber and said combustion chamber.

4. A burner disposed in an open chamber for admitting separate suppliesof a pair of gaseous mediums to an area outwardly of said chambercomprising,

(a) an inner cone member,

(b) a shell carried by said inner cone member in spaced relationtherewith whereby to define an inner passageway between said inner conemember and said shell and an outer passageway between said shell and theperipheral wall of said chamber,

(c) said inner cone member being axially movable to a plurality ofpositions in which said inner and outer passageways are in fluidcommunication with said area outwardly of said chamber,

(d) said shell having an upper conically shaped portion for providingdifferent directions of flow for said gaseous mediums admitted into saidarea from said inner and outer passageways, respectively, wherebyintimate mixing of said mediums is obtained,

1(6) said peripheral wall of said open chamber being cylindrical wherebythe size of the opening of said outer passageway into said area iscontrolled by the extent of said inner cone member axial movement forcorrespondingly adjusting the velocity of the gaseous medium admittedthrough said outer passageway,

(f) said area outwardly of said chamber being the combustion chamber ofa hot blast stove and said gaseous mediums comprising air and fuel,respectively, and

(g) a baffle provided on said inner cone member adjacent the exit ofsaid inner passageway for deflecting the gaseous medium exiting fromsaid inner passageway in a direction away from said inner cone member.

5. A burner in accordance with claim 4, wherein the combustion chamberwall adjacent the exit of said outer passageway includes portions fordeflecting the gaseous medium exiting from said outer passageway in adirection away from said wall.

6. A burner in accordance with claim 3, wherein baffle is provided onsaid inner cone member adjacent the exit of said inner passageway fordeflecting the gaseous medium exiting from said inner passageway in adirection away from said inner cone member, and wherein the combustionchamber wall adjacent the exit of said outer passageway includesportions for deflecting the gaseous medium exiting from said outerpassageway in a direction away from said wall.

7. A burner in accordance with claim 6, wherein the inner cone memberincludes a peripheral passageway for passing a cooling mediumtherethrough, and wherein cooling means are provided externally of saidopen chamber.

8. A burner in accordance with claim 1, wherein there is furtherprovided a fixed inner tube defining a partition betweeen said inner andouter passageways, and wherein said shell has a lower tubular portion intelescoping relation with said inner tube for guiding said shell duringaxial movement of said inner cone member.

9. A burner in accordance with claim 1, wherein said area outwardly ofsaid chamber is the combustion chamber of a hot blast stove and whereinsaid gaseous mediums comprise air and fuel, respectively.

10. A burner in accordance with claim 1, wherein said inner cone memberis axially movable toa position in which it defines a closure for saidopen chamber.

11. A burner in accordance with claim 9, wherein said inner cone memberis axially movable to a position in which it defines a closure betweensaid open chamber and said combustion chamber.

12. A burner in accordance with claim 9, wherein the direction of flowof said mediums results in flames of combustion directed away from thewall of said combustion chamber.

13. A burner in accordance with claim 1, wherein the inner cone memberincludes a peripheral passageway for passing a cooling mediumtherethrough.

14. A burner in accordance with claim 13, wherein cooling means areprovided externally of said open chamber.

References Cited UNITED STATES PATENTS 4/1924 Hetsch 239-414 3/1964 Mohret al. 431

EDWARD G. FAVORS, Primary Examiner

